This invention relates generally to an apparatus and method for conducting a fluid into an annulus within a well and for thereafter providing an open channel communicating with the well. This invention relates more particularly, but not by way of limitation, to a cup type casing packer shoe with closing sleeve and pumpout seats and to a method of cementing a tubing string in a well without having to drill out through the tubing string after the cement has been emplaced.
In wells for the production of oil and gas, casing cemented into a borehole can wear out and leak due to corrosion, wear from various well operations, etc. When this occurs, the casing is typically repaired by cementing a smaller tubing string, such as a smaller diameter casing, inside the old casing.
To cement the smaller string in the damaged string, a packer shoe can be used on the bottom of the smaller string to control the cement during the cementing operation. One type of packer shoe is shown in U.S. Pat. No. 4,961,465 to Brandell.
Prior types of packer shoes have typically required a drillout procedure to clear an entrance into the inner flow channel of the smaller tubing string once the string has been cemented. There are some applications, however, where such drillout is not desirable. For example, if the smaller tubing string which has been cemented is plastic-lined, it would not be desirable to drill out because the lining could be damaged during the drilling procedure.
To use such prior types of packer shoes, a blockage is formed in the shoe by dropping a ball down the tubing string to seal against a ball seat at the lower end of the packer shoe. Cement is then pumped down the tubing string and out one or more ports in the packer shoe above the blockage formed by the ball and ball seat. After the cement has been emplaced, a drill is lowered through the tubing string to drill out the ball and ball seat to open the internal channel of the tubing string to fluid flow into or out of the well below the annular seal established by the packer carried on the shoe at the bottom of the column of cement which has been pumped into the well above the packer.
In view of the foregoing, there is the particular need for a packer shoe which can create the needed blockage to force cement out through ports of the packer shoe, but which can be thereafter unblocked without a drilling procedure. There is also the need for a related method of cementing a tubing string in a well without having to drill out through the tubing string after the cement has been emplaced. More generally, there is the need for an improved apparatus and method for conducting a fluid into an annulus within a well and for thereafter providing an open channel communicating with the well.